Matsya Purana 227.54

227.54

amānuṣīṣu puruṣo udakyāyāma yoniṣu.
retaḥ siktvā jale caiva kṛcchraṃ sāntapanaṃ caret .. 227.53 ..

A wise man should not indulge with the above mentioned class of ladies, nor should he marry one's relation, a fallen woman, a woman in menses. He should also abstain from unnatural offence and indulging with lower animals. One who does so should keep up Kṛichhrasantapana penance to purify himself of the sin. If one discharges one's semen in water, one is to perform Kṛichhrasantapana vrata.—52-53